Turntable



Nov. 6, 1923. 1,472,792-

A. Y. DODGE ET AL TURNTABLE Filed April 5, 1925 3 Sheets-Sheet 1 ii-m A. Y. DODGE ET AL TURNTABLE Filed April 5,

1925 3 Sheets-Sheet 2 Patented Nov. 6, 1923.

ilhlt AE-s ADIEL Y.

CONSIN, ASSIGNORS TO FREEMAN MA CONSIN, A CORPORATION OF WISCONSI TURNTABLE.

Application filed April 5, 1923. Serial No. 629,984.

T0 (1 1." whom-it may; concern.

Be itknown that we, Aninn Y. Donor and ROBERT J. Srarz, citizens of the United States, residing at Racine, in the county of Racine and State of Wisconsin, and Wind Point, Racine, in the county of Racine and State of lVisconsin', respectively, have invented new and useful Improvements in Turntables, or" which the. following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification. Our invention relates to turntables, and more particularly turning loaded trucks. Such a turntable is useful for instance in building roads, where the material to be used is hauled in trucks on the sub-grade and is dumped near the place where it is to be used. It'might be ditlicult and sometimes impossible to turn the truck around on the sub-grade on its own wheels, due to the narrow width of the sub grade and the fact that ditches might be at the sides of the sub-grade, so portable turntables are being used, located near the place where the material is to be used, onto which the truck can be run and on which it can be turned around so that it can back up to they place where the material is to be used and there dumped.

When the road building progresses up to or near the turntable, the turntable is then dragged ahead some distance so as to allow the road building to progress.

fine of'the objects of our invention is to provide an improved turntable which will be what we term selfbalancing, and selflifting; self-balancing in that when the truck is drivenonto the runway, the truck wil be automatically balanced so that the center of gravity will be close to the axis of rotation of the turntable, and self-lifting". in that when the table tilts to a self balancing position. the approach end .ofthe runways will be swung up high enough so as to clear the forms at the side of theroad or other obstructions. p

A urther object of. our invention is to provide a turntable which will be very easy to operate, so that one man can easily turn it. under any conditions.

A "further object of our invention is to to portable turntables for:

' table. so that as the provide improved means for lubricating the anti-friction supports for the table.

A further object of our invention is I to provide a turntable which is so designed that it will be very light, thereby cutting the cost of construction and making for ease of operation. I v i Further objects will appear fromvthe de tailed description to follow appended claims.

In the drawings in which two forms of our invention are shown- Figure 1 is a plan View of a turntable-embodying our invention; a Fig. 2 is a side view of theturnta'ble showingv he approach endresting on the road- Fig. 3 is a section on the line 3-3 of Fig. 1; f V: V

Fig. dis a side view of alatch construction;

Fig. 5 is a plan View showing a lighter,

cheaper form of turntable embodying our invention Fig.6 is a side elevation of t-he'turntable shownin Fig. 5; and I ,Fig. 7 is a section on the line 7-7 of Fig.5.

Referring now to. the drawings in detail,

and first to Figs. 1, 2 and 3 and 4, theconstruct-ion shown comprises ,a slidable base, I

in the nature of a skid or scow, which can be dragged from place to place, and a bridge member comprislng a pair of spaced runways, mounted on said slidable base for rotation'about a vertical axis, and also tiltably mounted-to permit'the approach end of the runway to be brought down on the roadway for the truck to be driven upon the bridge.

The bridge is tiltably mounted on a 111 crum member, which fulcrum-member is located.nea'rthe axisof rotation of the turn-j truck is driven nponto the bridge, thebridge will tilt, and move'to horizontal position, atthe moment that the center of gravity of the truck passes thev axis of the fulcrum, the approach end of the bridgebeing. thus lifted from the roadway, and being raised high enough so that when way or other obstructions.

and from the the table is turned, the end of the bridge -will clear the forms at the side of the road- A stop member is provided in order to prevent the bridge from tipping too far when the center of ravity of the truck passes the axis of the ulcrum, and an additional auxiliary stop member is provided, mounted onthe bridge itself, which will engage the roadway, to stop the tilting movement of the bridge in case the primary stop member fails to stop the tilting movement of the bridge. 7

The rotatable and tiltable bridgemember comprises a pair of spaced runways 10, of substantially channel cross section, as shown in Fig. 3, these runways 10 being united by cross pieces 11', which extend between and underneath the runways lO. The bridge is tiltably mounted on a transversely extending fulcrum member 12, which extends underneath the runways 10, and atransversely ex tending stop member 18, similar in construction to the fulcrummember 12, is provided to limit the tipping movement of the runway when the center of gravity of the load passes the axis'of the fulcrum memberlQ.

Both the fulcrum member 12 and the stop member 13 are mounted forrotation together about a vertical axis along with the bridge, the fulcrum member and the stop member being mounted on a rotatable dished-member 141, which forms the main rotatable support for the fulcrum member, the stop member,

and the bridge. This dished member 1 1 is rotatably mounted in an outer dished member 15, a ,circularlyarranged anti-friction device being provided between the inner. and outer dished members, as indicated at 16, the dished members being provided with ball races to receive the balls 17 of the anti-friction device. 1

The shape of the dished members 14- and 15, which;is similar to that of a tank head, is such that they are well-adapted to resist the stresses -to which they are subjected, the deep upwardly extending flanges providing great strength and rigidity at the places where these-are required.

The space between "the inner and outer dished-membersis used as an oil reservoir so that the balls. operate in an oil bath.

The outer dished member-15 is-mounted on the slidable base 18. A central axial antifriction bearing is provided to take care of the'greater portion of the weight of the turntable and truclcmounted. thereon, in'the form of a vertical thrust hearing as indicated.at.19., As indicated'in Figs. 1 and 3, the fulcrum member 12 and the stop member 13 are each supported at three points, as indicated at 20, 21 and 22. The two points of support 20 and 21-are on the rim or upwardly extending flange of-the inner rotatabledished member 14, while the central point of support 22 is on the .two beam members 23 which carry the load down to the thrust bearing 19.

crum member 12, tne runway is supported by As intimated above, when the truck is driven onto the runway, and the center of gravity of the load passes the axis of the fultips to horizontal position, and the driver thereupon immediately throws out his clutch and puts on his brakes, bringing the truck to a stop within a foot or so, so that the center of gravity of the load is very near the center of rotation of the turntable. This brings probably of the weight of the load on the central axial thrust hearing at 19. The driver can tell immediately when the bridge begins to tip, as he can feel it move, see it tipping, and hear the click when the bridge strikes the stop member 13.

Tn order to prevent foreign substances, such as dust and the like, from getting into the oil bathbetween the dished members 14 and 15,.dirt excluding means are provided,

comprising an annular felt member 21secured to a downwardly extending annular skirt member 25 which in turn is secured by means of clips 26 to an annular angle member 527, riveted to the upwardly extendingflange 28 of the inner rotatable dished member 14.

It will be noted that the annular felt piece engages'a flat surface, so that there is no tendency for the felt to bind or wrap about the rotatable member, as might be the case if the feltmember engaged a cylindrical surface.

The central portion of the outer dished member 15' rests on a heavy plate 29 secured to the bottom of the slidable base 18, while the outer portion of the dished member 15 an annular angle member 30, having one flange secured to the dished member asindicated at 31, and the other flange secured to the bottom of the slidable base as indicated at 32. 7

.Oil is supplied to the space between the inner and outer dished members through a supply pipe 33 screwed into the inner dished member, the supply pipe being provided 'with a screw plug 34: for closing the filling opening. V a

be two dished members 14: andlfi may be pressed from sheet metal. The slidable base may be formed of plates and structural. shapes- The beams 23 which support the balancing portion of the load may be I- bcams. The cross pieces 11 may be structuralor pressed shapes. The runways 1.0 as shown in Fig. 3 comprise the plate on which the truck wheels 36 rest, the inner angle member 37, to assist in taking care of the bending strains and to form an inner guide flange, and a deep built-up outer flange member, formed of two angle sections 38 and 39, to take care of the main bending stresses, and to form an outer guide flange. It will be-noted'that the inner flange 37 is comparatively shallow so that there is am- The central axial thrust bearing 19 00mprises a journal member 41 secured to the fixed outer dished member 15 by means of bolts 42, this journal member having an'annular flange portion held between the upper and lower plates 43 and 44 which are secured to the inner rotatable dished member 14 by means of bolts 45. V I The auxiliary stop for limiting the tipping of the bridge in case the main stop member 13 fails to stop the tilting movement, comprises a pivoted foot member 46, pivoted to the end of the bridge at 47, and operated by means of a hand lever 48. This hand lever 48 may also be used for swinging the bridge about its vertical axis,

In turning the table, after the truck has been driven onto it, the lever 48 is swung as indicated in the direction of the arrow A, to fold the pivoted foot 46 up into line with the bridge which leaves the hand lever 48 ex-.

tending outwardly into a position convenient for use in swinging the table around. This pivoted foot 46 is intended for use only as an auxiliary or emergency stop, in case the truck should run so far forward as to cause the bridge to tip downwardly about the stop member 13 as a fulcrum, or if for any other reason the main stop member 13 should fail to stop the bridge in its tipping movement.

hen a truck is about ready to run up onto the bridge, an operator takes hold of the far end of the bridge and lifts up on it, to bring the approach end of the bridge down onto the roadway as shown in Fig. 2 so that the truck can run up onto it. In order that the operator may not have to hold up on the bridge after he has tilted it up, a yielding latch device is provided (Figs. 2 and 4). This yielding latching device comprises a reciprocable latch or cam member 49, having an inclined portion 50'whichengages the upper edge of the stop member 13, a coil compression spring 51 being provided, surrounding this latch member and thrusting it with sutlicienttorce against the fulcrum member, to hold the bridge in its uptilted position. One end of the latch member s carried by a swinging link 52, the other endbeing slidable in a bracket 53 secured to 'the bridge. The inclination of the edge 50 ot the latch member which engages the stop member 13 is so arranged and the spring 51 isso designed that this latch member will yield as soon as the center of gavity of the truck passes the fulcrum member '12 to per brake drum 40, whileheavy bending. carry the stress mit the bridgeto tilt into horizontal position.

In moving the turntable from place to place, it may either be dragged supported by the skid or slidable base 18, which'isturned up at both endsas indicated at 54 and 55 to facilitate this operation, or one end of the turntable may be supported on a trailer, and the other end on therear end of one of the.

trucks, and the turntable hauled along behind the truck.

In order to facilitate this latter operation,

means are provided whereby when the bridge is picked up, and supported betweenthe trailer and the truck,the skid: or slidable base also will be bridge and supported underneath the bridge.

This construction, as shown in detail in Fig.

3, comprises a heavy bolt at 56, heavy enough to support the weight of the skid or slidable baseat the dished members 13 and 14 and associated parts, this bolt being loosely connected at one end to the loosely connected at the cross pieces 11.

This loose connectionof the bolt 56 and the other. end to one of picked up along with the- I-beam 23 and parts connected thereby permits the necessary tilting of the bridge. In order to take up some of the slackness of this connection when the bolt 56 is used as a support in car rying the parts suspended underneath, a

latch member or. plate 57 is provided,.which whenthe turntable is in use, is turned to lie in the channel portion of the cross piece 11, and when the turntable is being-carried from one place to another as above described, it is turned to bring the ends of the latch member 57 to rest on the oppositely disposed flanges of the cross niece 11. Theuse and operation of the turntable has been outlined inconnection with the descripa tion of the construction. Briefly, the turntable is set up at one side of the sub-grade, near the place where the material is to be dumped. As a loaded truck approaches, the bridge is swung around so as to extend longitudinally of the roadway. and the attendant tips up the far end of the bridge, which is the'end provided with the pivoted foot 46, until the other end of the bridge, which is the approach end, rests on the sub=grade. The bridge will be held in tilted position by means of the latch 49. The driver of the truck then drives his truck up onto the bridge. When the center of gravity of the loaded truck passes the axis of the fulcrum.

member 12, the bridge and the truck will tilt about this fulcrum, the latch 49 yielding readily to permit thistilting. The moment the bridge and the truck begin to tilt, the driver of the truck throws out theclutjch and throws on the brakes and brings the truck to 'a stop on the bridge in a short distance,

probably a foot or so. .As the axis of the fulcrum member 12 isabout afoot from the axis of rotation of the bridge, the center of gravity of the load will be brought to rest approximately over the vertical axis of ro-.

tat-ion of the bridge, and therefore substantially over the main thrust bearing at 19, so that the main portion of the load will be carried by this main thrust bearing at 19. The bridge is stopped in its tilting movement and held in horizontal position by means of the stop member 13, which is located about a foot from the far side of the vertical axis of rotation of the bridge, and about 2 feet from the fulcrum member 12. The bridge and the truck are thus supported about equally by the fulcrum member 12 and the stop member 13.

In case the brakes should fail to work, or if for any reason the truck should overrun until the center of gravity passes the stop member 49, the emergency or auxiliary stop hold the brldge 111 or pivoted foot 46 will substantially horizontal position 'by its engagement with the roadway.

This foot 16 will also stop the tilting movement of the bridge in case the momentum of the bridge and truck should be so 'reat that the bridge would continue to tilt or push bar 48, swinging the bridge through substantially 180 degrees, and thus turning the. truck end for end.

The driver of the truck now backs the truck off, In this backing off movement,the bridge will begin to tilt as soon as the center of gravity passes the fulcrum member 12. and this tilting movement will continue until the end of the bridge which has been referred to as the approach end rests on the F ground. thus permitting the truck to be readily baoked down off the bridge without much jolting.

The driver then continues to back up the truck until it is where the material is to be dumped. After dumping the truck, the driver is all ready to start off for another load. As the bridge extends longitudinally of the roadway, there is ample room for the truck to pass it without getting off the subgrade.

Suitable means are provided for preventing the bridge from sliding endwise on the fulcrum and stop members, and from slipping oif sidewise. For this purpose, clips 58 are secured to the under side-of the runram-gar way 10 and the flanges of the-fulcrum and stopmembers are cut away as indicated at 59, for cooperation with these clips 58. Endwise movementof the bridge is prevented by the engagement of the clip 58 with the web Referring now toFigs. 5, 6 and 7, the

construction shown therein is lighter and cheaper than that previously described. The

runway may be similar to the one previously described, and also the slid-able base or skid. In this construction, the inner and outer dished members and ball race are dispensed with and the fulcrum member 60 and the stop member 61 are supported for rotation together on a vertical post-62 which is suitably supported on the slidable base or skid 63. V

The fulcrum member 60 and the stop member 61 are suspended from a rotatable head 64: by vmeans of four angle clips 65. This rotatable head 64 is rotatable on the upwardly extending pin or post 62. The verticalv pin 62 and the rotatable head 64 are supported on a stationary head 66 which is secured to the slidable skid or base 63. Any suitable means, not necessary to be described in detail, may be provided for holding the runways against lateral or longitudinal sliding on the fulcrum member 60 and the stop member 61. These means may be similar to those disclosed in connection with the form previously described, or any other suitable means may be provided. The bridge in this form may be provided with a pivoted foot 67 and hand lever 68 just as in the form previously described. The use and opera tion of this bridge is substantially the same as in the form previously described.

WVhile we have shown but two forms of our invention, it is obvious thatit may be embodied in other forms covered and defined by the appended claims.

Having thus described our invention,

what we claim as new and desire'tosecure by United States Letters Patent is:

1. A portable turntable comprising a base slidable on the roadway, a fulcrum member and a stop'member spaced from said fulcrum member, said fulcrum member and said stop member both being mounted on said slidable base and rotatable together about a vertical axis. and a runway for a truck tiltablymounted on said fulcrum, and tiltable from a position in which one end of the runway is low enough for the truck todrive onto the runway, to a position in which the runway engages the stop member and is held in substantially horizontal position, whereby when the truck is driven onto tilt to a horizontal position in. which it .is

held by said stop member, when thecenter of gravity of the truck passes the fulcrum member. 4 v

2. A portable turntablecoinprising base slidable on the roadway, a fulcrum nember, a stop member, spaced from said fulcrum member, both said fulcrum member and said stop member being mounted onsaidslidable base and rotatable together about a vertical,

axis, and a runway for a truck tiltably mounted on said fulcrum, andt-iltable from a position in which the approach endof the runway-is low enough for the truck to; drive thereon, to a substantially horizontal position, in which the runway engages said stop member, and an auxiliary, stop 'member mounted on said runway at the end opposite the approach end, for engaging the roadway to limit the tilting movement of the runway in case the stop member fails to stop the tilt-. ing moveinen v v 3. A portable turntable comprising-a. base slidable on the roadway, a fulcrum member, a stop member, spaced from said fulcrum member, both said fulcrumpmember and said stop member being mounted on said slidable base and rotatabletogether about a vertical axis, and a runway for a truck tiltably mounted on said fulcrum, and tiltable from a position in which the approach end of the runway is low'enough for the truck to drive thereon, to a substantially horizontal position, in which the runway'en gages said stop member, and anauxiliary stop member mounted on said runwayat the end opposite the approach end, for engaging the roadway to limit the tilting "movement of the runway in case the stop member fails to stopthe tilting movement, said auxiliary stop being pivotally mounted on the runway to fold out of the way when the runway is being rotated.

4. A portable turntable comprising a base slidable on the roadway, a.,cir'cularly'farranged anti-friction device mounted o'n's'aid slidable base, a fulcrum member, a-stop member spaced from said fulcrum member,

said fulcrum member and stop member being supported for rotation together about a vertical axis by said anti-friction device, and a runway for a truck tiltably mounted on said fulcrum, and tiltable from a position in which the approach end of the runway is low enough for a truck to drive thereon, to a substantially horizontal position in which it engages said stop member, whereby as the truck is driven onto the runway, the runway will automatically 'tilt to horizontal position and be held there when the centerd of gravity of the truck passes the fulcrum, the axis of said fulcrum lying within the circle of the anti-friction device, whereby when the truck and runway are in 'baiaiiia 1 horizontalfposition, the center of gravity of the load will'lie within the v circle of the antisfriction device. 5

5, A portable turntable comprising a base slidable on the roadway, a circularly-ar ranged anti-friction device mounted onsaid slidable base, an- 'axialjly located anti-friction dev1ce, a -fulcrum member, a stop member spaced fron fsaid fulcruinmember, said; ful:

crum member and stop member being; sup-i ported for rotation together about averti; cal axisby said antiefriot on dev ces, and a nw y e a t ck; til b vmounted on said fulcrum,;and tiltable-from a positionin :5

which the approach'end of therunway is low enough; for a truck to drive; thereon to a substantially horizontal position in which it engages said stop member, whereby when the truck is driven onto thefrunway, ,the

runway will automatically tilt to horizontal position and be heldthere when' the center of gravity of'the truck passesthe first fulcrum, the axis of said fulcrum lying within the circle .of the circularly arranged antifriction device, ,whereby' when the] truck and runway are balanced in horizontal. po-

sition,the balanced portion-of the load will be carried principallyfby the axially located anti-friction device,

portion of the load willbe carried by the circularly arranged emanation device.)

7 6. A portable turntable comprising a base slidable on the roadway, a fulcrum member, a stop 'member. spaced from said fulcrum membeijfsaid fulcrum" member "and, sto memberbothbeing mounted onsaid slid able base for, rotationtogether about a vertical axis, arunway forQ' a-truck tiltably ,mounted on'said fulcrum member, and tiltable from .a position in'whi'ch'lthe approach and the unbalanced end "of the'runway'is loWQenQugh for the truck to drive thereon, horizontal position inwhich 'it'is held by said stop ;member, whereby as the truck-is T f.

'driyenl overthe runway,flthe "runway will automatically tilt to afhorizontal position in whichf'it is. held by said, stop member when'the center of gravity of the truck passesthe fulorum'member, and means for holding the approach end of the'runway in lowered positionwhen'tilted by the attendant for the truck to drive thereon, whereby the attendant does not have to hold up the other'end of the runway after he has tilted it'up, H i v i '7; A portable turntable comprising a base slidable on' the roadway, a fulcrum memto' a v substantially ber, a stop member spaced from said fulcrum V 7 member, saidefulcrum member and stop memberboth being mounted onsaid slidable base for rotationto gether about a; vertical axis, a runway for a truck tiltably mounted on said fulcrum member, and tiltable from a position in'lwhich the approach end of therunwayis low enough for the truck to truck to drive thereon, whereby the attendant does nothave to hold upthe other end of the runway after he has tilted it up;

8. A portable-turntable comprising a base slidable on the roadway, a fulcrum member, a stop member spaced from said fulcrum member, said fulcrum member and stop member both being mounted'on said slidable base for rotation together about a'vert'ical axis, a runway fora truck tiltably mounted on said fulcrum member, and tiltable from a position in which the approach end of the runway is low enough for the truck to drive thereon, to a substantially horizontal position in which it is held by said stop member, whereby as the truck is driven over the runway, the runway will automatically tilt to a horizontal position in whichit is held by said stop member when the center of gravity of the truck passes the fulcrum member, andspring means for hol-ding the approach end of the runway in lowered position when tilted by theattendan't for the truck to drive thereomwhereby the attend ant does not have to hold up'the other'end ofthe runway after he has tilted it up.

9. A portable turntable comprising'a base slidable on the roadway, a fulcrum member, a stop member spaced from said fulcrum member, said fulcrum member and stop member both beingmounted on said slidable base for rotation together about a vertical axis,- a runway for a truck tiltably mounted on saidfulcrum member, and tiltable from a position in which theapproach endflof the runway is low enough for the truck to drive thereon, to a substantially horizontal position in which it is held by said stop membeig' whereby as the truck is driven over the runway, the runway will automatically tilt to a horizontal position in which it is held by said stop member when the center of gravity of the truck passes the fulcrummember, and yielding means for holding the approach end of the runway in lowered position when tilted by the attendant for ,the truck to drive thereon, whereby the holding means will yield to permit the runwayto .tilt to horizontal position whenthe center of grav ity of the truck passes the fulcrum member.

10. A portable turntable comprising a base slidable on a roadway, a fulcrum member, a stop member spaceddfrom said fulcrum member, said fulcrum member .and' stop member being mounted on said slidable base for rotation together about a vertical axis, a runway for a truck tilt ably mounted on said fulcrum member and tiltable from a position in which the approach end of the runway is low enough for the truck to drive thereon to a horizontal po sition in which it is held by said stop member, w hereby it'the truck is driven onto the runway, the runway will automatically tilt to a horizontal position in which it is held by said stop member, when the center of gravity of the truck passes the fulcrum member, and anti triction means for supporting said runway, comprising. axially located central anti-friction device for supporting the balanced portion of the load,

and a circularly arranged anti-friction'device coaxial with said central friction device, for supporting the unbalanced portion ofthe load. V

11. A portable turntable con'iprising a base slidable on the roadway, and a bridge member for supporting a truck mounted on said slidable base for rotation about a vertical axis, said bridge member comprising a pair of spaced runways, one on each side of said bridge, for supporting the wheels of the truck, and cross members extending between and underneath said runways, said runways being of channelled cross sections, theoin- 3- nerflange of the channel section being lower than the brake drum of the truck to provide clearance, and the outer flange of the chan nel being considerably higher than the inner fiang efto provide strength to resist bending, said cross member serving to carry load, from the horizontal web portion of channel and from the inner 'flange of channelto the strong outer flange of channel. 1

12. A portable turntable comprising a baseslid'able on the roadway, a runway for a truck'mounted on said slidable base l'or rotation about a vertical axis, and anti-triction means for supporting said runway for rotation, comprisingan outer circular dished member having a peripheral strengtheningflange mounted on said slidable base, a circular, inner dished member having a peripheral strengthening flange within said outer dished member, and rotatable therein, onwhich said runway is mounted, and a circularly arranged antifriction device between said dished members.

13. A portable turntable comprising a bridge slidable on the roadway, a runway for a truck mounted on said slidablebase for rotation about a vertical axis, and antifriction meansfor supporting said runway for rotation comprising an outer circular dished member having an upwardly ex tending peripheral strengthening flange mounted on said slidable base, a circular innerdishedmember having an upwardly the the the Hill the i within said outer dished member and ro-' extending peripheral strengthening flange,

tatable therein, on which said runway is mounted, a circularly arranged anti-friction device between said dished members, and means for supplying lubricant to the antitriction device between said dished members.

14. A portable turntable comprising a bridge slidable on the roadway, a runway for a truck mounted on said slidable base for rotation about a vertical axis, and antitriction means for supporting said runway for rotation comprising an outer circular dished member having an upwardly extending peripheral strengthening flange, mounted on said slidable base, a circular inner dished member having an upwardly extending peripheral strengthening flange. within said outer dished member and rotatable therein, on which said runway is mounted, a circularly arranged anti-friction device between said dished members, and means for supplying lubricant to the antifriction device between said dished members, and means for preventing foreign sub stances from entering between the flanges of said dished members.

A portable turntable comprising a bridge slidable on the roadway, a runway tor a truck mounted onisaid slidable base for rotation about a vertical axis, and antifriction means for supporting said runway for rotation comprising an outer circular dished member having an upwardly extending peripheral strengthening flange, mounted on said slidable base, a circular inner dished member having an upwardly extending peripheral strengthening flange, within said outer dished member and rotatable therein, on which said runway is mounted, a circularly arranged anti-friction device between said dished members, means for supplying lubricant to the anti-friction device between said dished members, and means for preventing foreign substances from-entering between the flanges of said dished members, comprising an annular'felt member engaging the upper edge of the flange of the outer dished member and mounted on the inner dished member.

16. A portable turntable comprising a base slidable on the roadway, .a fulcrum member, a stop member spaced from said fulcrum member, a'runway for a truck tiltably mounted on said fulcrum member and tiltable from a position in which the approach end of the runway is low enough for the truck to drive thereon to a substantially horizontal position in which it is held by said stop member, and anti-friction means for supporting said fulcrum member and said stop member for rotation about a substantially vertical axis comprising an outer circular dished member having an upwardly extending peripheral strengthening flange, mounted on said slidable base, acircular inner dished member having an upwardly extending peripheral strengthening flange, within said outer dished member and rotatable therein, on the flange of which said fulcrum member and stop member are mounted, and a circularly arranged antifriction device between'said dished members. Y

In witness whereof, we have hereunto subscribed our names.

ADIEL Y. DODGE. ROBERT J. STATZ. 

